Topic Contents

Alport Syndrome

National Organization for Rare Disorders, Inc.

ImportantIt is possible that the main title of the report Alport Syndrome is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.

Synonyms

Hereditary Nephritis

Hematuria-Nephropathy Deafness

Hereditary Deafness and Nephropathy

Hereditary Nephritis With Sensory Deafness

Hemorrhagic familial nephritis

Disorder Subdivisions

None

General Discussion

Summary Alport syndrome is a rare genetic disorder characterized by progressive kidney disease and abnormalities of the ears and eyes. There are three genetic types. X-linked Alport syndrome (XLAS) is the most common; in these families affected males typically have more severe disease than affected females. In autosomal recessive Alport syndrome (ARAS) the severity of disease in affected males and females is similar. There is also an autosomal dominant form (ADAS) which affects males and females with equal severity. The hallmark of the disease is the appearance of blood in the urine (hematuria) early in life, with progressive decline in kidney function (kidney insufficiency) that ultimately results in kidney failure, especially in affected males. About 50% of untreated males with XLAS develop kidney failure by age 25, increasing to 90% by age 40 and nearly 100% by age 60. Females with XLAS usually do not develop kidney insufficiency until later in life. They may not develop kidney insufficiency or failure at all, but the risk increases as they grow older. Both males and females with ARAS develop kidney failure, often in the teen-age years or early adulthood. ADAS tends to be a slowly progressive disorder in which renal insufficiency does not develop until well into adulthood. Individuals with Alport syndrome can also develop progressive hearing loss of varying severity and abnormalities of the eyes that usually do not result in impaired vision. XLAS is caused by mutations in the COL4A5 gene. ARAS is caused by mutations in both copies of either the COL4A3 or the COL4A4 gene. ADAS caused by mutations in one copy of the COL4A3 or COL4A4 gene. Alport syndrome is treated symptomatically and certain medications can potentially delay the progression of kidney disease and the onset of kidney failure. Ultimately, in many cases, a kidney transplant is required.

Introduction The disease we now know as Alport syndrome was first described in the British medical literature in the early years of the 20th century. In 1927 Dr. Cecil Alport published a paper describing the association of kidney disease and deafness in affected individuals. Many additional cases were described in the literature and the disorder was named after Dr. Alport in 1961. Alport syndrome is often discussed with a related disorder known as thin basement membrane nephropathy (TBMN). Many cases of TBMN are caused by different mutations in the same genes that cause the autosomal recessive and dominant forms of Alport syndrome. TBMN is characterized by persistent microscopic blood in the urine (hematuria) in a similar pattern as seen in individuals with Alport syndrome. However, unlike Alport syndrome, TBMN is rarely associated with symptoms outside of the kidney (extrarenal abnormalities) and additional kidney findings such as protein in the urine (proteinuria), high blood pressure (hypertension), kidney insufficiency, and kidney failure rarely develop. It is extremely important to distinguish these disorders from one another because TBMN is much more common and a much milder disorder. The spectrum of disease that includes TBMN and Alport syndrome is sometimes referred to as collagen IV-related nephropathies. For more information on TBMN see the Related Disorders section of this report.

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use.
How this information was developed to help you make better health decisions.

Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.